Forming a hardmask capping layer

Abstract

A capping layer is formed over a hardmask layer to increase the etch resistance and overall performance of the hardmask layer. Embodiments include forming a hardmask layer over a substrate and forming a capping layer on the hardmask layer, the capping layer including a stack of at least two nanolayers.

What is claimed is: 
     
       1. A method comprising:
 forming a hardmask layer over a substrate; and 
 forming a capping layer on the hardmask layer, wherein:
 the capping layer comprises a stack of either: at least three alternation nanolayers of silicon carbide (SiC) and silicon carbon nitride (SiCN), at least three alternating nanolayers of boron nitride (BN) and titanium nitride (TiN), or at least three alternating nanolayers of SiC and BN. 
 
 
     
     
       2. A method according to  claim 1 , comprising forming the capping layer and the hardmask layer to a total thickness of less than or equal to 40 nanometers (nm). 
     
     
       3. A method according to  claim 2 , comprising forming the capping layer and the hardmask layer to a total thickness of 30 to 40 nm. 
     
     
       4. A method according to  claim 1 , comprising forming the capping layer to a thickness of 10 to 30 nm, wherein the stack includes 100 nanolayers. 
     
     
       5. A method comprising:
 forming a titanium nitride (TiN) hardmask layer over a substrate; and 
 forming a capping layer on the TiN hardmask layer to a thickness of 10 to 30 nm, wherein: 
 a total thickness of the TiN hardmask layer and the capping layer ranges from 30 to 40 nm, and 
 the capping layer comprises a stack of either: at least 20 alternating nanolayers of silicon carbide (SiC) and silicon carbon nitride (SiCN), at least 20 alternating nanolayers of boron nitride (BN) and titanium nitride (TiN), or at least 20 alternating nanolayers of SiC and BN.